Editorial methodology
Rules before recommendations.
This site uses versioned decision trees written from manufacturer support material and public safety guidance. It does not call an LLM at runtime.
Model gate
A supported brand prefix and washer family are required. A mismatch stops the tree and sends the user to the manufacturer manual lookup.
Node-level evidence
Every question and outcome is linked to the source used for that claim. The exact model manual and recall notice always control.
Confidence boundary
An error code identifies a condition, not automatically a failed part. Internal component conclusions require model-specific testing.
Repair-or-replace rule
Warranty coverage is checked first. Otherwise the tool divides a written repair estimate by the delivered replacement price. At 65% or above it leans replace; from 50% it also considers age of eight years or a repeated failure. From 40% to 64% it labels the choice borderline. These are disclosed site rules, not manufacturer findings.
Content lifecycle
Each guide records its review date, evidence summary, and citations. Decision trees are tested for dead ends, missing safety outcomes, missing evidence, and valid model examples during every build.